Botulinum toxin treatment of apraxia of eyelid opening in progressive supranuclear palsy: report of two cases.

We report two patients, with postural instability and dystonic parkinsonism whose adjunctive disabling feature was blindness due to an inability to reopen the eyes after voluntary closure of the eyelids, as in apraxia of lid opening (ALO). Supranuclear downgaze paresis permitted the diagnosis of progressive supranuclear palsy (PSP) in one case. Electromyographic studies showed a loss of normal reciprocal inhibition between the levator palpebrae and the pretarsal portion of the orbicularis oculi, with a cocontraction of these two antagonist muscles. The evoked blink reflex, tested with the paired shock technique, showed enhanced recovery of R2 response. Botulinum toxin A injections directed toward the junction of the preseptal and pretarsal parts of the palpebral orbicularis oculi muscle improved eyelid motility in both patients. Successive static and dynamic balance training and development of compensatory strategies for visual scanning deficits reduced gait imbalance, the number of falls, and the disability level as measured on the Northwestern University Disability Scale.